In the forestry industry various work machines, such as wheeled and tracked feller bunchers, may be utilized in the tree-harvesting process. A felling head may be mounted to the feller buncher by a knuckle boom to position the felling head in proximity to a standing tree. The felling head may have one or more large saw discs with peripheral teeth that are rotated by a hydraulic motor so as to cut into the tree. The hydraulic motor may be coupled to, and powered by, the hydraulic system of the feller buncher. The felling head may have a large grapple or other members to clamp around a cut tree and carry it to a transport machine, such as a forwarder, or to a stacking location.
Even with large diameter saw discs of modern felling heads, large trees may have a larger trunk diameter such that operator may need to make successive cuts to fell the tree. The large size of the saw disc generates very large angular velocities when rotated at cutting speeds. To reduce power demands on the hydraulic system, kinetic inertia may be relied upon for a cutting operation as way to supplement or supplant the hydraulic power required for the motor to rotate the saw disc. Further, the effect of inertia may need to be compensated for in order to control the depth of a cut. The effect of inertia and the complexities of positioning the felling head may both need to be managed when making multiple cuts into the tree.